Macrofauna bentônica de ambiente inconsolidado da zona de plataforma na região do Terminal Portuário Do Pecém, Ceará, Brasil

Abstract

The continental shelf region is mainly composed of sandy and muddy sediments, providing habitat for diverse species of benthic marine invertebrates. The biodiversity of the Brazilian shelf regions is still poorly understood, especially in the northern northeast (Southwest Equatorial Atlantic). However, this biota is susceptible to many impacts, particularly in port areas, where chemical spills, coastal erosion, and the appearance of exotic species are common. The objective of this study was to analyze, qualitatively and quantitatively, the benthic macrofauna in the port region of Pecém (Ceará, Brazil) to identify possible spatial and temporal variations. Four sampling campaigns were carried out in 2024 and 2025, two during the dry season and two during the rainy season, with sediment sampling performed using a Van Veen dredge in four unconsolidated areas in the windward region of the port terminal. In total, 48 samples were collected, which were washed through a 0.5 mm mesh to retain macrofauna, preserved in 70% ethyl alcohol, and taken to the laboratory where the animals were processed, identified into major taxa, and photographed. A non-parametric multivariate analysis (one-way PERMANOVA), cluster analysis, and ordination analysis using NMDS were performed, all using the Bray-Curtis similarity index. A non-parametric multivariate analysis (one-way PERMANOVA), cluster analysis, and ordination analysis using NMDS were performed, all employing the Bray-Curtis similarity index. PERMANOVA indicated no significant temporal difference, however, there was a significant spatial difference in macrofauna composition. Among the sedimentological profiles, significant differences were observed only at reef points. The study presented a benthic macrofauna composition similar to that observed in other studies in shelf areas. However, it should be noted that, in some of these studies, other abiotic factors such as depth and the amount of organic matter in the substrate were determining factors for the macrofauna composition. Greater investment in biodiversity research in shallow equatorial shelf zones is necessary to provide knowledge aimed at their conservation.